1. Field of the Invention
The present invention relates to a round baler for agricultural harvested crop and including a housing formed of a front housing and a rear housing connected with the front housing with a possibility of a pivotal movement relative thereto, a variable volume bale chamber having a delivery opening and limited, in an axial direction, by side walls of the baler housing and, in a radial direction, by at least one flexible transporting and pressing belt, which is guided over deflection rolls, and by at least one pressing roller which is arranged adjacent to a respective deflection roll, a pick-up device arranged in a region of the delivery opening, and a pivot device supported in the baler housing for pivoting the transporting and pressing belt, with increase of a bale diameter, from a start position of the transporting and pressing belt to its end position.
2. Description of the Prior Art
German Publication DE 198 10 074 A1 discloses a round baler with a variable volume bale chamber which is limited, on one hand, by a large bottom roller, which is provided downstream of a pick-up device, and two upper pressing rollers arranged above the pick-up device and secured, with a possibility of rotation, in the baler housing, and, on the other hand, by a transporting and pressing belt guided over a lower deflection roll arranged adjacent to the bottom pressing roller and an upper deflection roll arranged adjacent to one of the upper pressing rollers. The bale chamber of the known round baler has a triangular shape. In addition to the belt support mechanism which provides for release of the belt length as the diameter of the bale increases, there is provided an additional belt tensioning device in a form of a belt deflection roll which is pivoted by the bale as it grows and which is arranged above the upper pressing roller. This additional belt tensioning device provides, without any complex lever arrangement or an active spring, for increase of the belt tension between start and end positions in response to growth of the bale. Because the belt deflection roll of the additional tensioning device is freely pivotable, it often slips during processing of different harvest swath, in particular, when the swath piles up. This leads to the application of a non-uniform pressure to the bale, as it is being formed, and as a result, non-round bales can be produced. However, the most important drawback of the known round baler consists in that the bottom pressing roller and the adjacent to it, in the rotational direction, deflection roll remain stationary relative to each other, with the spacing between them corresponding to the end diameter of a bale. As a result, at the start of bale formation, a relatively large transitional step exists between the bottom pressing roller and the adjacent deflection roll. At small and intermediate diameters of the bale, this deflection roll is spaced from the bale and, therefore, does not apply any compression force to the bale. If the deflection roll had been arranged higher, at large diameters, a greater deflection, pivotal movement, would have required which, in turn, would have resulted in the change of the shape of the bale and an increased power consumption.
European Publication EPO 496 069 A1discloses a round baler with at least one pivotable deflection roll that is deflected by a special actuator to one side to provide for uniform tensioning of the transporting and pressing belt over the entire width of the bale chamber.
An object of the present invention is to provide a round baler with a variable volume bale chamber in which the transitional region between a pressing roller and adjacent to it deflection roll is always remain optimal with increase of the bale diameter.
Another object of the present invention is to provide a round baler with a variable volume bale chamber which permits bale diameter variations, from 0.6 m to 2 m, which could not be achieved up to now, without adversely affecting uniformity of produced bales, their density, and without a noticeable change in the power consumption.